Some indoor units of air conditioners are equipped with a movable panel, a drive portion, and an opening and closing mechanism. The movable panel is, for example, a panel that moves so as to open and close an opening such as an intake port. The drive portion generates a driving force to move the movable panel. The opening and closing mechanism is a mechanism to move the movable panel by a driving force of the drive portion, and for example, it comprises a gear which transmits a driving force of a motor and the like. In addition, indoor units of air conditioners are equipped with a main body casing that houses a heat exchanger, a ventilation fan, and the like, and the drive portion is often provided in the main body casing. Consequently, with conventional indoor units of air conditioners, in many cases, the opening and closing mechanism is also provided in the main body casing (see for example, Japanese Patent Publication No. 07-12821).
On the other hand, many of the recent indoor units of air conditioners are equipped with a front grill that is mounted to the main body casing. The front grill is mounted to the front of the main body casing, and has openings such as an intake port and an outlet. With such an indoor unit of the air conditioner, the above described movable panel is movably provided so as to open and close the openings of the front grill. Then, the movable panel opens and closes the openings by the drive portion and the opening and closing mechanism provided in the main body casing. In other words, even when the front grill is mounted to the main body casing, since the drive portion is provided in the main body casing, the opening and closing mechanism is also provided in the main body casing in many cases.